Refrigerating plant



. 9, 1941. F. J. CUMMING REFRIGERATING PLANT 2 She'ets-Sheet 1 FiledApril 24, 1939 j? van 2 01 jb d J Cznnmz'qg Dec. 9, 1941. F. J. CUMMING2,265,634

REFRIGERATING PLANT Filed April 24, 1939 2 Sheets-Sheet 2 H E9. 3 n

Ford 6511772772729 Patented Dec. 9, 1941 UNITED STATES PATENT OFFICEREFRIGERATING PLANT Ford J. Cumming, Minneapolis, Minn. applicationApril 24, 1939, Serial No. 269,575

16 Claims.

disclosed and claimed in my pending application a S. N. 260,993, filedMarch 10, 1939, and entitled Refrigerating plant.

In the said pending application there is disclosed a novel arrangementof a low temperature refrigerating unit in connection with a coldstorage room and a relatively warm room or compartment. The saidlowtemperature unit, as preferably designed, involves a metallic casingexposed in the storage or low temperature room and containing a lowtemperature heat exchanger.

The said application also involves novel means of defrosting therefrigerating coils or elements within the casing. In practice it hasbeen found that with the metallic casing of the refrigerating unitexposed in the cold room'there was sometimes difficulty in preventingfreezing of the water resulting from defrosting on the bottom of thecasing or in the drain passage leading therefrom. My present inventionprovides a simple and eflicient means for remedying that defect withoutproviding heavily insulated conduits for the drain and without making itnecessary to insulate the casing of the refrigerating unit.

Certain of the features illustrated in the drawings of this applicationare common to those in my pending application and these common featureswill be noted after first describing the figures of the drawingsillustrating the present invention.

Referring to the drawings:

Fig. 1 is a view partly in plan and partly in horizontal sectionillustrating the invention, some portions being broken away;

Fig. 2 is a transverse vertical section taken on the irregular line 2-2of Fig. 3;

Fig. 3 is avertical section taken on the line 3-3 of Fig. 1; and

Fig. 4 is a vertical section taken on the line 4-4 of Fig. 1.

The elements of the present drawings which correspond to the drawings ofthe earlier application are indicated by the same numerals, to wit; thenumeral 5 indicates a processing room or compartment and the numeral 6indicates a cold storage or lockerroom.

For illustration it may be stated that in practied the temperaturemaintained in the cold storage room or compartment 6 will usually bemaintained in the processing room or compartment 5 will usually be from70 to 30.

As shown, a normally closed door l0 leads from the room 5 into the room6. The low temperature unit shown involves a box-like metallic casing I9 in which a low temperature heat exchanger 20 and a motor driven fan orblower 2i are located. The casing I9 is preferably hung high or near theceiling in the room 6 and is provided with two air intake ports 24 and25, the former being exposed to cold storage room 6 and the latter beingexposed to the warm processing room 5. These intake ports 24 and 25 areadapted to be opened and closed by valves or gates 24' and 25. Also thecasing is provided with a main cold air discharge pipe or conduit 26that opens into the room 6 through one or more discharge conduits 30adapted to be opened and closed by valve acting louvers or dampers 3|.Pipe or conduit 26 is provided with a branch 32 that opens into theprocessing room 5 and is adapted to be opened and closed by a valveacting damper or gate 33.

Located in the main pipe or conduit 26 between the branch 32 and outlet30 is a damper or valveacting closure 34. The low temperature heatexchanger 20 is shown as supplied with refrigerating fluid through pipes22 leading from a suitable compressor 23. i

In the use of the apparatus so far described, as will more fully appearfrom the description of the said prior application, closures 25' and 32will be closed, and dampers or closures 24', if and 34 will be open whenthe refrigerating unit is used to produce the low temperature in theroom 6. When, however, the apparatus is to be defrosted, closures 25'and 33 will be opened and the closures 24' and 34 will be closed so thatthe warm air from the room 5 will be circulated through the casing I9 todefrost the refrigerating coils 20.

In accordance with my present invention, the bottom of the casingcompartment containing the low temperature heat exchanger is locatedabove the casing bottom and the drain pipe leading from the heatexchanger of the casing is located in a by-pass formed in the bottom ofthe casing l9 and through which a part of the warm air from the room 5will be circulated to keep the bottom proper of the refrigeratingcompartment and the drain pipe leading therefrom at a temperature abovethe freezing point. In the pre-' ferred form of this arrangement, thecasing i9 is provided with a raised deck or false bottom 25 from zero toplus 10 F.; while the temperature on which the refrigerating coils andthe motor propelled fan or blower are mounted. This deck 35 is airspaced from the bottom of the casing to aflord an auxiliary air passage30 between the deck II and the bottom of the casing. The receiving endof this auxiliary air passage II is adapted to be opened and closed by avalve act-. ing damper or gate I! and the delivery end of said auxiliarypassage opens into the upper part of the casing through a large airpassage a 10+ cated quite close to the eye of the fan or blower.

As a means for adjusting and variably-setting the gate or damper 31there is s'hojwn'ajs provided a depending chain or operating cables asthat depend through the bottom of the casing. Opening upwardly throughthe false bottom or deck 3! and located within the auxiliary air passage3. is a water conveying drain pipe 40. This drain pipe 40 is extendedthrough the auxiliary air passage II to a point outside of the coldstorage room or compartment 30 and from thence, by an extension I, isextended outward and downward to a suitable point of discharge. Asshown, the extension pipe 4! extends into the relatively warm room I andfrom thence outward to a suitable point of discharge or to a suitablereceptacle that may be located within the said room or compartment 5. Ofcourse, it is desirable to keep the drain pipe out of contact with thesur-, faces of the casing, so that it will be surrounded by and subjectto'the influence of a current 0,1,

warm air during defrosting periods.

In the defrosting operation above indicated, the damper or gate 31 willbe opened to such an extent that there will be enough warm air drawnthrough the auxiliary air passage 38 to keep the drain pipe and the deck35, from dropping to the freezing point. This obviously preventsfreezing of water on the deck or bottom .35 and in the drain pipe. Ofcourse, the main volume of air passes between and around therefrigerating coils of the heat exchanger 20 to melt the ice therefrom,and from thence to the intake of the fan or blower, and the air drawn inthrough the auxiliary air passage 36 will also be taken in through theeye of the fan and discharged from the fan.

It follows from the foregoing that, for the defrosting operation, thecirculation of the rela- ,tively warm air from the warm room I will beinto the casing and from thence back into. the said warm room orcompartment 5.

n the deck 35 just forward of the air intake passage 38 is a raisedtransverse flange 42; and

a just forward of the radiator 20 on said deck is a similar transverseraised flange 43. These flanges and the sides of the casing form on thedeck 35 a shallow water collecting drain pan that prevents the waterresulting from defrosting from running directly into the air duct 33 andfrom coming into contact with the extreme bottom of the casing, whichlatter, as noted, is subject to the low freezing temperature in the room6. a By the means described, the water is prevented from coming intocontact with the cold bottom 1 of the casing where it would be likely tofreeze, and is caused to run out freely through the drain i pipe 40.

relatively cold and relatively warm room, a refrigerator casing exposedwithin said relatively cold room, said casing having damperuipped airintake and discharge conduits leading from and to said relatively warmroom, a heat exchange radiator located in said casing, a motor drivenfan in said casing, and a drain pipe extended from said casinglongitudinally of and within the air intake conduit and leading intosaid relatively warm room.

2. The structure deflned in claim 1 in which said casing has a raiseddeck forming a false bottom and'drip pan to which said drain pipe isconnected and from which said drain pipe leads to said relatively warmroom. I

3. m a cold storage refrigerating plant, a cold storage room wherein airis refrigerated to below freezing temperatures, an associated warm roomwherein the. temperature is maintained above freezing, an air conduitexposed to the freezingtemperature in the cold storage room and havinginlet and outlet openings exposed to the warm air above freezingtemperature in said associated warm room, a low temperatureheatexchanger located in said conduit intermediate said openings, saidconduit being equipped with valve means for opening and closing the sameto pas- I sage of warm air therethrough to and from said Broadlyconsidered, the casing i9 forms an enlarged part of the conduits leadingto and from a the cold storage room 6, and to and from the j warm room5. Hence, the casing i9 and its 1 extended conduits may hereinafter bejointly referred to as a conduit having inlet and outlet openings.

What I claim is: 1. In an air conditioning installation, separated warmroom, and water collecting and conveying means positioned and arrangedwithin said conduit to collect water precipitated from the heatexchanger during defrosting period and convey the same outwardly of thecold storage room through an extended end portion of said conduit thatopens into said warm room, whereby the collecting and conveying meanswill be maintained under the influence of warm air circulated throughthe conduit from the warm room 4. The structure deflned in claim 3, infurther combination with blower means for force circulating air throughsaid conduit.

5. The structure deflned in claim 3, in which the said water conductingmeans extends through the warm air intake end portion of said conduit.

6. The structure deflned in claim 3, in which the said water collectingand conducting means is air spaced from the bottom and top of theconduit and in which the air spaces above and below the same are open togitudinally of the conduit.

7. The structure deflned in claim 3, in which the water collecting andconveying means includes a drip pan positioned within the conduit tointercept and collect water dripping from the heat exchanger defrostingperiods, said drip pan being air spaced from the top and bottom of theconduit so as to permit free passage of air above and below the same.

v 8. The structure deflned in claim 3, in which the water collecting andconveying means includes a drip pan positioned within the conduit tointercept and collect water dripping from the heat exchanger defrostingperiods, said drip pan being air spaced from the top and bottom of theconduit so as to permit free passage of air above and below the same,and further includes a water conductor leading from the drip pan andoutwardlyof the cold storage room through an extended end portion of theconductor that opens in to the warm room, said water conductor being airspaced from the cold surfaces of the conduit substantially throughoutthat porpassage of air lontion thereof within the cold storage roomexposed portion of the conduit.

9. In a cold storage refrigerating plant, a cold storage room whereinair is refrigerated to below freezing temperatures, an associated warmroom wherein the temperature is maintained above freezing, an airconduit exposed to the freezing temperature in the cold storage room andhaving valve controlled inlet and outlet openings exposed to the warmabove-freezing temperature air in said associated warm room and alsohaving inlet and outlet openings exposed to freezing air in the coldstorage room, a low temperature heat exchanger located in said conduitintermediate the inlet and outlet openings, said conduit being equippedwith valve means operative to open the conduit to passage of airtherethrough from and to the cold storage compartment and to close thesame topassage of warm air therethrough from and t6 the warm room or toclose the conduit to passage of air therethrough from and to the coldstorage compartment and open the same to passage. of warm airtherethrough from and to said associatedv warm room and water collectingand conveying means positioned and arranged within said conduit tointercept and collect water precipitated from the heat exchanger duringdefrosting periods and convey the same outwardly of the cold storagecompartment through an extended end portion of said conduit that opensinto the warm room, whereby the conducting and conveying means will bemaintained under the influence of warm air circulated through theconduit from the warm room during defrostlng periods.

10. The structure defined in claim 9 in which the water conducting andconveying means extends through the warm air intake end portion of theconduit.

11. The structure defined in claim 9 in which the said water collectingand conducting means is air spaced from the bottom and top of theconduit and in which the air spaces above and below the same are open topassage of air longitudinally of the conduit.

12. The structure defined in claim 9, in combination with blower meansfor force circulating air through said conduit.

13. The structure defined in claim 9, in which the water collecting andconveying means includes a drip pan positioned within the conduit tointercept and collect water dripping from the heat exchanger defrostingperiods, said drip pan being air spaced from the top and bottom of theconduit so as to permit free passage of air above and below the same.

14. The structure defined in claim 9, which further includes a waterconductor leading from the drip pan and outwardly of the cold storageroom through an extended end portionof the conductor that opens in tothe warm room, said water conductor being air spaced from the coldsurfaces of the conduit substantially throughout that portion thereofwithin the cold storage room exposed portion of the conduit.

15. The structure defined in claim 9, in which the said water conductingmeans extends through the warm air intake end portion of said conduit.

16. Structure defined in claim 1, in which said warm air intake passagewithin said casing is divided, one branch thereof leading to the intakeof the fan through said heat exchanger and the other branch thereofleading to the intake of the fan past the heat exchanger, and in whichsaid drain pipe is located in and is extended longitudinally. throughthe last noted branch of said warm air intake conduit.

FORD J. CUMMING.

